Sheet metal and other structural plate products are conventionally cut to size, and apertures in the plate are punched or otherwise created according to predetermined design considerations.
Quality control requires that the finished plates be remeasured to confirm the accuracy of their length, width, and the precise location of the apertures.
Heretofore, it has been a practice in such quality control operations to utilize a table surface having an elongated slot extending at right angles from a straight gauge means. A movable protruding pin rides in the slot from a movable carriage. A suitable electronic measuring device is associated with the pin and a digital display.
A plate having a straight edge is abutted against the straight stop after the pin has been moved longitudinally in the slot to provide space between the pin and the stop to permit the plate to rest on the table surface. By bringing the pin to the edge of the plate opposite to the stop, and actuating the measuring device, the precise length of the plate can be confirmed.
If there are one or more apertures in the plate that need to have their locations verified, the plate is tilted upward so that the pin can be moved longitudinally in the slot to ultimately be in a position to penetrate the aperture being measured when the plate is again laid flat on the table surface. Having to move the pin while the plate is laying on the table surface consumes unnecessary time and adds to the labor of the measuring device.
Therefore, it is a principal object of this invention to have a selectively retractable pin in the slot of such a measuring table so that the pin can be moved from position to position in a retracted condition even when a plate is resting on the top supporting surface of the measuring table.
It is a further object of this invention to utilize such a retractable pin in a measuring table whereby the pin can be easily retracted by the operator
These and other objects will be apparent to those skilled in the art.